This invention relates to a biofeedback system particularly useful in rehabilitation therapy. The invention relates, more particularly, to a biofeedback system suitable in the treatment of motor neuron lesions particularly in the retraining of muscles and reeducating patients who have suffered strokes or have been subjected to neurologic trauma.
A recent summary of biofeedback techniques appears in an article of Basmajian, John V., MD, "Biofeedback in Rehabilitation: A Review of Principles and Practices", Arch. of Physical Medicine and Rehabilitation, Volume 62, No. 10, pages 469-475, October 1981. The article describes known techniques of using electronic equipment to reveal to patients and therapists certain physiologic events and to teach patients to control events by manipulating the event related signals, which usually are visual and/or acoustic. Biofeedback has gained recognition especially in the treatment of upper motor neuron lesions, particularly in retraining muscles and inducing relaxation of muscles of stroke patients and the like. The broad concepts of using electrogoniometers, pressure-sensitive and position-sensing devices as transducers is recognized.
Another summary, S.J. Middaugh, "Electromyographic Feedback: Effects on Voluntary Muscle Contractions in Normal Subjects", Arch. of Physical Medicine and Rehabilitation, Volume 63, No. 6, pages 254-259, June 1982, recognizes the possibility of using a voltage controlled oscillator producing a tone which is related to electromyographic feedback as an improvement in simple trial-and-error-learning.
Among body and limb position sensing devices are usually switches such as disclosed in the U.S. Pat. No. 3,614,763 to Yannuzzi entitled "Prone Position Alarm", issued Oct. 19, 1971. The mercury switch is positioned within a housing which also includes an audio oscillator which sounds an alarm, the housing being operatively associated with a clip which may be placed on a user's belt. Another proposal for the use of a mercury switch in association with a limb position sensing device is known from the U.S. Pat. No. 3,885,576 to Symmes entitled "Wrist Band Including A Mercury Switch To Induce An Electric Shock", issued May 27, 1975.
Of more general interest, are the teachings in the U.S. Pat. Nos. 4,191,949 and 3,208,062 to Myers and Gregory, respectively, these patents disclosing respectively a position warning device, associated with an otherwise conventional belt, and a signal device for alerting a user to the nodding of his head.